California Current Ecosystem LTER

Size Fractionated Chlorophyll (Process Cruise)

Title
Size fractionation for total Chl a within the surface layer and calculated size distribution of total Chl a from discrete bottle samples collected during CCE LTER process cruises in the CCE region, 2006 - 2017 (ongoing).

Abstract
Water for size fractionation of chlorophyll a is sampled from ~10m depth (surface layer) in the CCE study area. The size distribution of total chlorophyll a is determined by filtering water though filters of differing pore sizes. These are then extracted in acetone and analyzed fluorometrically with Turner Designs 10-AU Fluorometer on CCE Process cruises (since 2006, ongoing). Chlorophyll a and taxon-specific pigments (chlorophylls and carotenoids) are qualitatively and quantitatively characterized in the lab onshore by several size fractions (< 1µm to > 20µm) utilizing High Performance Liquid Chromatography (HPLC) analysis. The samples analyzed within the CCE region are used to develop a metric for phytoplankton community structure that can be used to monitor its state and changes thereof over time.

Keywords
marine, measurements, chlorophyll a, phytoplankton, seawater, depth, chlorophyll, Primary Production, RAPID: Responses of the California Current Ecosystem to El Nino 2015-16

LTER Data System Record
http://dx.doi.org/10.6073/pasta/b247c5328129b1193693632254700fb3
Projects
California Current Ecosystem LTER

Creators
Goericke, Ralf (rgoericke@ucsd.edu)

Contact
CCE LTER Information Manager (ccelter.im@gmail.com)

Data

table SizeFractionatedChlorophyll
Main data table for dataset
Rows: 317
Columns: 21
View / Download

Methods


General Methods
Size fractions for total Chl a were processed by filtering a known volume of seawater (0.10 to 0.25 L), thru 5 different filter pore sizes. Each filter type, Whatman GF/F; 1, 3 and 8 µM nucleopore filter; and 20µM Nitex filter, was sampled in triplicate. Filters were extracted in 7.0 mls of 90% acetone and stored in the dark at -18°C for approximately 24 hours. Samples were thawed in the dark until reaching room temperature and then analyzed on a Turner Designs 10-AU Fluorometer. Chlorophyll a was calculated from fluorescence (et al). Size fractionation samples were analyzed in the field. Pre and post cruise fluorometer calibrations, chlorophyll a (Sigma Cat#C6144), were acquired from the CalCOFI group and averaged

General Methods
Cruises are quarterly with 66 CalCOFI-SIO and 9 SCCOOS stations samples (stations maybe cut depending on weather and time). Size Fractionations started on the augmented CalCOFI-SIO cruises in November 2004.